Sandbox term explained
Filter by Google applied for young sites. The sites in the domain zone .RU do not fall in the sand, may the reason is not in the domain zone, but in the site russian language.
Such signs can be defined in the sandbox your website or not: the website is cached by Google, but is not in the results at low competitive queries, it is also not necessary in the first place when searching a domain name. The reason for getting a site in the sandbox, usually in the rapid growth of backlinks. This filter is temporary and depending on a number of factors that lasts from one to six months.
What to do if your website has imposed this filter? It is recommended to stop automatically set links to the site, put up some links from trust resources and wait for their indexing. The better back links your website has the faster it is possible to avoid the dog.